Cylinder throw mechanism for printing presses



United States Patent [72] Inventor Charles A. Harless Fort Worth, Texas[21] Appl. No. 606,754 [22] Filed Jan. 3,1967 [45] Patented Sept. 8,1970 [73] Assignee Harris-Intertype Corporation Cleveland, Ohio acorporation of Delaware [54] CYLINDER THROW MECHANISM FOR PRINTINGPRESSES 6 Claims, 6 Drawing Figs.

[52] U.S.Cl 101/143, 101/220 [51] Int. Cl..' 1341! 13/28 [501FieldofSearch 101/137, 139,140,143,144,145,177,179,180,182,184, 185,217, 218, 220, 229, 247

[56] References Cited UNITED STATES PATENTS 2,874,636 2/1959 Royer etal. lOl/2l8 1,524,816 2/1925 Dalby 101/352 1,582,039 4/1926 Harrold101/218 1,590,742 6/1926 Goulding...'. 101/218 Primary Examiner- RobertE. Pulfrey Assistant Examiner-.1. Reed Fisher A tt0rney-- Yount, Flynnand Tarolli ABSTRACT: An improved printing press includes a cylinderthrow mechanism for moving a pair of printing cylinders between a throwon position in which they define a printing nip and a throw offposition. The cylinder throw mechanism includes a first eccentric andtoggle linkage for operating one of the printing cylinders between thethrow on and throw 011' positions. A second eccentric and toggle linkageis provided for operating the other printing cylinder between the throwon and throw off positions. These toggle linkages are operated inresponse to operation of a third toggle linkage. This operation of thecylinder throw mechanism moves high points of eccentricity on the twoeccentrics through a plane extending through the axes of rotation of theprinting cylinders.

Patented Sept. 8, 1970 3,527,165

INVENTOR CHARLES A. HA/PLESS r RNEYS Patented Sept. 8, 1970 Sheet 2 of 2N VEN 70/? CHARLES A. mam

By "M FIGES CYLINDER THROW MECHANISM FOR PRINTING PRESSES The presentinvention relates to a cylinder throw mechanism for establishing animpression or printing pressure between a pair of cylinders, and inparticular to a cylinder throw mechanism for simultaneously moving apair of cooperable printing cylinders between a throw on position inwhich they are in operative printing relation with each other and athrow off position in which they are out of printing relation with eachother.

An important object of the present invention is to provide a new andimproved cylinder throw mechanism for simultaneously moving a pair ofprinting cylinders of a rotary printing press between a throw onposition in which they are in operative printing relation with eachother and a throw off position in which they are out of operativeprinting relation with each other, and in which the cylinder throwmechanism is of a simple and economical construction, reliable inoperation, and so constructed and arranged that it is effective tomaintain the cylinders in the throw on position with a maximummechanical advantage so as to prevent accidental movement thereof towardtheir throw off position.

Another object of the present invention is to provide a new and improvedcylinder throw mechanism of the character referred to and wherein thecylinder throw mechanism includes a movable member operatively connectedwith the printing cylinders for moving the same between their throw onand throw off positions and a toggle linkage connected with said movablemember for moving the latter when actuated, and wherein the togglelinkage is substantially in an on center position, preferably a slightlyover center position, when the printing cylinders are in their throw onposition whereby the printing cylinders are effectively held in thisposition and accidental movement thereof toward their throw off positionis prevented.

Yet another object of the present invention is to provide a new andimproved cylinder throw mechanism for simultaneously moving a pair ofcylinders between a working position and another position, and in whichthe cylinder throw mechanism comprises first and second toggle linkagesrespectively connected with the cylinders and which have a common linkmember and a third toggle linkage connected with the common link memberof the first and second toggle linkages and operable to move the latterto move the cylinders between their positions when actuated, and whereinthe third toggle linkage is preferably arranged such that it is in asubstantially on center or slightly over center position when thecylinders are in their working position whereby the cylinders are heldin their working position against movement.

A further object of the present invention is to provide a new andimproved cylinder throw mechanism, as defined in the next precedingobject, and wherein the first and second toggle linkages are arrangedsuch that they are in a substantially on center or slightly over centerposition when the cylinders are in their working position to furtherhold the cylinders in their working position against movement.

The present invention further resides in certain novel constructions andarrangement of parts, and further objects and advantages thereof will beapparent from the following detailed description of an illustratedembodiment of the present invention and in the accompanying drawingsforming a part of the present specification and in which similarreference numerals are employed to designate corresponding partsthroughout the several views, and in which:

FIG. 1 is a schematic view ofa printing press embodying the presentinvention; FIG. 2 is a fragmentary side elevational view of part of theprinting press shown in FIG. 1;

FIG. 3 is a fragmentary sectional view taken approximately along line3-3 of FIG. 2;

FIG. 4 is a side elevational view with parts thereof shown in section ofthe preferred embodiment of the cylinder throw mechanism of the presentinvention;

FIG. 5 is a fragmentary side elevational view like that shown in FIG. 4but with certain parts thereof shown in a different position; and

FIG. 6 is an isometric view of part of the cylinder throw mechanismshown in FIGS. 4 and 5.

The present invention provides a novel cylinder throw mechanism forsimultaneously moving a pair of cylinders between working andnon-working positions. Although the novel cylinder throw mechanism ofthe present invention is susceptible for use in various kinds ofmachines or apparatuses, it is particularly useful for simultaneouslymoving a pair of cooperating printing cylinders of a rotary offsetprinting press between a throw on position in which they are disposed inoperative printing relationship with each other and a throw off positionin which they are out of printing relation with each other, and for thepurposes of illustration it is herein shown and described as beingembodied in a rotary offset lithographic printing press 10.

Referring to the FIG. 1 of the drawings, the rotary offset printingpress 10 is there shown as comprising upper and lower rotatablecooperating blanket cylinders 12 and 14 defining a printing niptherebetween through which a web 15 to be printed is adapted to pass.The web 15, in the illustrated embodiment, is adapted to be printed onboth of its sides, with the blanket cylinder 14 being the impressioncylinder for the blanket cylinder 12 and the blanket cylinder 12 beingthe impression cylinder for the blanket cylinder 14. The press furthercomprises upper and lower rotatable ink transferring or plate cylinders16 and 18, respectively, disposed in operative ink transferring relationwith the blanket cylinders 12 and 14. As shown in FIG. I, the axes ofrotation of the plate cylinders 16 and 18 and the axes of rotation ofthe blanket cylinders l2 and 14 he in common vertical planes, designatedby reference numerals 19 and 20, respectively, with the plane containingthe axes of rotation of the blanket cylinders 12 and 14 being disposedon one side of or spaced from the plane containing the axes of rotationof the plate cylinders 16 and 18.

The blanket cylinders 12 and 14 are supported for movement toward andfrom the plane 19 containing the axes of rotation of the plate cylinders16 and 18 between a throw on position, as shown in FIG. 4, in which theyare disposed in operative printing relationship with each other and inoperative ink transferring relation or in contact with their respectiveplate cylinders 16 and 18, and a throw off position, as shown in FIG. 5,in which they are out of printing relation with each other and separatedfrom or out of contact with their respective plate cylinders 16 and 18.To this end, the blanket cylinders 12 and 14 have shafts 22 and 24 whichare rotatably journalled at their opposite ends within movable bearings25 and 26 which, in the preferred embodiment, are annular eccentricshaving circular outer and inner peripheries. The eccentrics 25 and 26are rotatably supported by the spaced side frames 27 of the printingpress 10 for rotation about their center axes, the center axes of theeccentrics being laterally spaced from the axes of rotation of theblanket cylinders 12 and 14. The eccentrics 25 and 26 have their highand low points of eccentricity H and L located apart and with their highradius points of eccentricity H being disposed beneath and above theaxes of rotation of the blanket cylinders 12 and 14, respectively.

The eccentrics 25 and 26 are adapted to be simultaneously moved from afirst position, as shown in FIG. 4, in which their high and low radiuspoints of eccentricity H and L are located on one side of a boundarydefined by planes 28 and 29 con taining the axes of rotation of theplate and blanket cylinders 16 and I2 and the plate and blanketcylinders 18 and 14, respectively, and the plane 20 and a secondposition, as shown in FIG. 5, in which their low radius points ofeccentricity L are located on the one side of the boundary and theirhigh radius points of eccentricity are located on the other side of theboundary or to the left of the plane 20. The eccentricity of theeccentrics 25 and 26 and the relative dispositions of the high and lowpoints of eccentricity thereof with respect to the plate and blanketcylinders are such that the shafts 22 and 24 and hence, the blanketcylinders 12 and 14 are caused to be moved away from the plate cylinders16 and 18 and away from each other in a direction away from the plane 19toward their throw off position when the eccentrics are moved from theirfirst position toward their second position and caused to be moved inthe opposite directions toward their throw on position when theeccentrics and 26 are moved from their second position toward theirfirst position.

The eccentrics 25 and 26 are adapted to be moved between their first andsecond positions by cylinder throw means, generally designated byreference numerals 30 and 31. The cylinder throw means 30 and 31 arerespectively operatively connected with the eccentrics 25 and 26 at theopposite ends of the shafts 22 and 24. Since both the cylinder throwmeans 30 and 31 are of an identical construction, only the throw means30 connected with the eccentrics 25 and 26 at the left ends of theblanket cylinders 12 and 14, as viewed in FIG. 6, will be described indetail, and corresponding parts of the throw means 31 will be given thesame reference numerals.

The cylinder throw means 30, sometimes hereinafter referred to as throwoff means, comprises first and second toggle linkages operativelyconnected with the eccentrics 25, 26, respectively, and which have acommon link member in the form of a lever 35. The lever 35 is rotatablysupported on a stub shaft 36 which in turn is fixed to the adjacent sideframe 28 of the printing press 10. The lever 35 at its other end isbifurcated and is pivotally connected to one end of a toggle link or arm38 by a pivot pin 39. The other end of the arm 38 is threaded andconnected to a generally rectangularly shaped block 39a by a pair ofnuts 39b disposed at the opposite ends of the block 39a, the block inturn being pivotally connected to the inner side of the eccentric 25 andalong the radial line passing through its high radius point by a pivotpin means 40. The lever 35 at its other end is also pivotally connectedto one end of a toggle link or arm 41 by a pivot pin 42. The other endof the arm 41 is threaded and connected to a generally rectangularlyshaped block 41a, by a pair of nuts 41b disposed at the opposite ends ofthe block 41a, the block in turn being pivotally connected to the innerside of the eccentric 26 and along the radial line passing through itshigh radius point by a pivot pin 43.

The cylinder throw means 30 further comprises a third toggle linkage 44connected with the lever 35. The third toggle linkage comprises a togglelink or arm 45 extending generally opposite to the arms 38 and 41 andwhich has one end pivotally connected to the other end of the lever 35by a pivot pin 46 and its other end pivotally connected to one end of alink or lever 48 by a pivot pin 49. The lever 48 at its other end isfixed or clamped to a shaft 50 having its opposite ends rotatablysupported by the side frames 28 of the printing press 10. The shaft 50is adapted to be rotated about its axis in opposite directions andfunctions to actuate the throw off means 30 to cause the eccentrics 25and 26 to be rotated. The shaft 50 can be rotated by any suitable orconventional means, such as by a hydraulic motor or, as here shown, by acrank 51 having one end fixed to one of the ends of the shaft 50.

As best shown in FIG. 4, the third toggle linkage 44 is in asubstantially on center position, preferably a slightly over centerposition, when the printing cylinders 12 and 14 are in their throw onposition and thereby provides a maximum resistance to movement oraccidental throwing off of the cylinders from their throw on position.The on center position occurs when the axis of the pivot pin 49 isaligned with the line of centers between the axis of the pivot pin 46 inthe axis of rota tion of the rotatable shaft 50. A slightly over centerposition is effected when the axis or center of the pivot pin 49 isspaced slightly from the line of centers and in a direction opposite tothe direction of movement of the pivot connection 49 that is to beprevented. As is apparent from FIG. 4, when the third toggle linkage 44is in its on center position movement of the lever 35 cannot take placeand hence, the cylinders 12 and 14 are held in their throw on position.

Moreover, the first and second toggle linkages are also in substantiallyon center positions, preferably slightly over center positions, when thecylinders 12 and 14 are in their throw on position, since the axes ofthe pivot pins 39 and 42 are in substantial alignment with the line ofcenters between the axis of the shaft 36 and the pivot axes of the pivotpins 40 and 43, respectively. Thus, the first and second toggle linkagesare also effective to maintain the cylinders 12 and 14 in their thrownon position.

When it is desired or it becomes necessary during operation of the pressto move the blanket cylinders 12 and 14 from their throw on position, asshown in FIG. 4, to their throw off position, as shown in FIG. 5, thecrank 51 is rotated in the direction of the arrow 52. Rotation of thecrank 51 in the direction of the arrow 52 causes the shaft 50 and thelever 48 to be rotated in this direction and to break the substantiallyon center position of the third toggle linkage 44. Movement of the lever48 in the direction of the arrow 52 in FIG. 4 causes the toggle arm 45to be moved toward the left which in turn causes the lever 35 to bemoved in the direction of the arrow 56 and break the on center positionof the first and second toggle linkages. Movement of the lever 35 inthis direction causes the toggle arms 38 and 41 to be moved toward theleft which in turn causes the eccentrics 25 and 26 to be moved in thedirection of the arrow 57 from their first position in which their highpoint of eccentricity is disposed to the right of the plane 20containing the axes of rotation of the blanket cylinders 12 and 14toward their second position in which their high point of eccentricityis located slightly to the left of the plane. Movement of the eccentrics25 and 26 from their first position toward and to their second positioncauses the blanket cylinders 12 and 14 to be moved from their throw onposition toward their throw off position in which they are separatedfrom or out of operative printing relation with each other and separatedfrom or out of contact with their respective plate cylinders 16 and 18.A suitable stop carried by the side frame 28 and which is engageable bythe crank 51 can be provided to enable the operator to readily determinewhen the throw off position for the blanket cylinders 12 and 14 has beenreached.

When the cylinders 12 and 14 are in their throw off position, as shownin FIG. 5, the high radius points ofthe eccentric 25 and 26 arepreferably disposed to the left of the plane 20 and thus, to enable thecylinders to be moved in a reverse direction toward their throw onposition it is necessary to cam or move the cylinder 12 upwardly againstthe downward force of its weight. This downward force is normallysufficient to hold the cylinders in their throw off position and preventaccidental movement thereof toward their throw on position. However, topositively prevent such movement a suitable releasable detent member 57carried by the crank 51 and which is cooperably engageable with a recess(not shown) in the side frame 28 is preferably provided, to positivelylock the cylinders in their throw off position.

To return the blanket cylinders 12 and 14 from their throw off position,as shown in FIG. 5, to their throw on position, as shown in FIG. 4, thecrank 51 is rotated in the opposite direction, as indicated by thedirection of the arrow 58. Movement of the crank 51 in the direction ofthe arrow 58 causes the shaft 50 and the lever 48 to be moved in thisdirection, which in turn causes the link 45 to be moved toward theright, as viewed in FIG. 5. Movement of the link 45 toward the rightcause the lever 35 to be moved in the direction of the arrow 60 which inturn causes the arms 38 and 41 to be moved toward the right. Movement ofthe arms 38 and 41 toward the right causes the eccentrics 25 and 26 tobe moved in the direction of the arrow 61 from their second positiontoward their first position. Movement of the eccentrics 25 and 26 fromtheir second position toward their first position causes the blanketcylinders 12 and 14 to be moved from their throw off position towardtheir throw on position in which they are in ink transferring relationor contact with the plate cylinders 16 and 18 and in operative printingrelation with each other.

The relative positions of the blanket cylinders 12 and 14 with respectto each other when in their throw on positions can be varied to enablewebs of different thicknesses to be printed and the printing pressure tobe varied. To this end, the eccentrics 25 and 26 are provided with thecars 72 and 73 which carry adjusting screws 74 and 75, respectively. Thescrews 74 and 75 are threadably engaged with the cars 72 and 73 and havetips 76 which form an abutment and which are adapted to abuttinglyengage radially extending abutment surfaces 77 of arcuately extendingabutments 78 fixed to the side frames 28 of the printing press. When theadjusting screws 74 are in abutting engagement with the adjacentabutments 78, the eccentrics 25, 26 are in their first position and theblanket cylinders 12 and 14 are in their throw on position.

From the foregoing, it should be apparent that the abutments 78 form astop and limit the movement of the eccentrics 25, 26 in the direction ofthe arrow 61 and thus, position the blanket cylinder 12 and 14 in theirthrow on position. By suitably rotating the adjusting screws 74 and 75and adjusting the nuts 3% and 41b on the arms 38 and 41, the position ofthe eccentrics 25 and 26 relative to the shafts of the blanket cylinders12 and 14 can be adjusted so as to adjust the gap or space between theblanket cylinders so as to compensate for various thickness of webs tobe printed.

From the foregoing, it can be seen that the hereinbefore enumeratedobjects and others have been accomplished and that a novel cylinderthrow on or throw off mechanism which is of a simple and economicalconstruction, reliable in operation, and which effectively holds theprinting or blanket cylinders 12 and lid in their throw on or throw offpositions has been provided.

lclaim:

l. A mechanism for simultaneously moving a pair of cylin' ders betweenworking and non-working positions comprising, rotatable eccentricsoperatively associated with said cylinders and having high and lowpoints of eccentricity for moving said cylinders from their working andnon-working positions, and means for rotating said eccentrics to effectmovement of said high and low points of eccentricity to thereby movesaid cylinders between their working and non-working positions, saidmeans comprising first and second toggle linkages respectively connectedwith the eccentrics of the pair of cylinders, said first and secondtoggle linkages including a common link member, said first togglelinkage further including an arm pivotally connected at one end to saidcommon link member and pivotally connected at the opposite end to one ofsaid rotatable eccentrics along a radius through the high point ofeccentricity of said one eccentric and inwardly of the outer arcuatesurface of said one eccentric, said second toggle linkage furtherincluding an arm pivotally connected at one end to said common iinkmember and pivotally connected at the opposite end to the other of saidrotatable eccentrics along a radius through the high point ofeccentricity of said other eccentric and inwardly of the outer arcuatesurface of said other eccentric, a third toggle linkage connected tosaid common link member and operable to move said common link member toeffect movement of said eccentrics when actuated, and means foractuating said third toggle linkage 2. A mechanism, as defined in claim1, and wherein said third toggle linkage comprises first and secondlinks pivotally connected together at their adjacent ends, said firstand second links at their other ends being pivotally connected to saidcommon link member and a fixed pivot means, respectively, said pivotalconnection between the adjacent ends of said first and second linksbeing substantially aligned with the line of centers of the pivotalconnections at the other ends of said first and second links when saidcylinders are in their working position whereby said third togglelinkage is effective to hold said cylinders against movement when intheir working position.

3. A mechanism, as defined in claim 2, and wherein said common linkmember of said first and second toggle linkages issupported for movementin o posite directions about a fixed pivot, sa1d first and second togg elinkages having an on center position and being substantially in theiron center positions when said cylinders are in their working position tofurther hold said cylinders against movement.

4. A mechanism as defined in claim 1, and wherein said pivotalconnection between the opposite end of the arm of said first togglelinkage and the high point of eccentricity of said one eccentric isdisposed on one side of the plane through the axes of said cylinderswhen said cylinders are in their working positions, said pivotalconnections between the opposite end of the arm of said first togglelinkage and the high point of eccentricity of said one eccentric beingdisposed on the opposite side of the plane when said cylinders are intheir non-working positions.

5. A mechanism for simultaneously moving a pair of cylinders betweenworking and non-working positions comprising, rotatable eccentricsoperatively associated with said cylinders for moving said cylindersbetween their working and nonworking positions, a first toggle linkageoperatively connected with one of said eccentrics for rotating said oneeccentric to move one of said cylinders between its working andnon-working positions, a second toggle linkage operatively connectedwith another of said eccentrics for rotating said other eccentric tomove the other of said cylinders between its working and non-workingpositions, said first and second toggle linkages including a commonmember mounted for pivotal movement about a first axis, said firsttoggle linkage further including a first arm pivotally connected at oneend portion to said common member for pivotal movement about a secondaxis and pivotally connected at the opposite end portion with said oneeccentric for pivotal movement about a third axis, said second and thirdaxes being in substantial alignment with said first axis when saidcylinders are in said working positions and partially defining a firstreference line extending through said axes, said second toggle linkagefurther including a second arm pivotally connected at one end portion tosaid common member for pivotal movement about a fourth axis andpivotally connected at the opposite end portion with said othereccentric for pivotal movement about a fifth axis, said fourth and fifthaxes being in substantial alignment with said first axis when saidcylinders are in said working positions and partially defining a secondreference line extending through said first, fourth and fifth axes andpositioned at an acute angle to said first reference line, and a thirdtoggle linkage connected to said common member and operable to move saidcommon member and said eccentrics to move said cylinders to theirnon-working positions, said second, fourth and fifth axes being locatedon the same side of said first reference line when said cylinders are intheir non-working positions.

6. In a rotary printing press as set forth in claim 5 wherein said firstarm is pivotally connected to said one eccentric along a radius throughthe high point of eccentricity of said one eccentric and said second armis pivotally connected to said other eccentric along a radius throughthe high point of eccentricity of said other eccentric.

